Patient-specific acetabular alignment guides

ABSTRACT

A method for inserting an acetabular implant into the acetabulum of a patient. The method includes engaging a patient-specific surface of acetabular alignment guide to a complementary rim surface and periacetabular area of a patient. A plurality of alignment pins are inserted through corresponding alignment apertures of the acetabular alignment guide and into the periacetabular area of the patient. The acetabular alignment guide is removed without removing the alignment pins from the patient. An alignment adapter is coupled to an acetabular inserter over the alignment pins and an acetabular implant is implanted using the acetabular inserter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 13/111,007filed on May 19, 2011, which claims the benefit of U.S. ProvisionalApplication No. 61/446,660 filed on Feb. 25, 2011.

This application is a divisional of U.S. application Ser. No. 13/111,007filed May 19, 2011, which is a continuation-in-part of: (1.) U.S.application Ser. No. 13/041,469 filed on Mar. 7, 2011, (2.) U.S.application Ser. No. 13/041,495, filed on Mar. 7, 2011, (3.) U.S.application Ser. No. 13/041,665 filed on Mar. 7, 2011, now U.S. Pat. No.8,535,387 issued on Sep. 17, 2013, and (4.) U.S. application Ser. No.13/041,883 filed on Mar. 7, 2011, each of which is acontinuation-in-part of U.S. application Ser. No. 12/978,069 filed onDec. 23, 2010, now U.S. Pat. No. 8,568,487 issued on Oct. 29, 2013,which is a continuation-in-part of U.S. application Ser. No. 12/973,214filed on Dec. 20, 2010, which is a continuation-in-part of U.S.application Ser. No. 12/955,361 filed on Nov. 29, 2010, now U.S. Pat.No. 8,591,516 issued on Nov. 26, 2013, which is a continuation-in-partof: (1.) U.S. application Ser. No. 12/938,913 filed on Nov. 3, 2010, and(2.) U.S. application Ser. No. 12/938,905 filed on Nov. 3, 2010, each ofwhich is a continuation-in-part of U.S. application Ser. No. 12/893,306filed on Sep. 29, 2010, which is a continuation-in-part of U.S.application Ser. No. 12/888,005 filed on Sep. 22, 2010, now U.S. Pat.No. 8,377,066 issued on Feb. 19, 2013, which is a continuation-in-partof U.S. application Ser. No. 12/714,023 filed on Feb. 26, 2010, now U.S.Pat. No. 8,241,293 issued on Aug. 14, 2012, which is acontinuation-in-part of U.S. application Ser. No. 12/571,969 filed onOct. 1, 2009, which is a continuation-in-part of U.S. application Ser.No. 12/486,992 filed on Jun. 18, 2009, which is a continuation-in-partof U.S. application Ser. No. 12/389,901 filed on Feb. 20, 2009, now U.S.Pat. No. 8,133,234 issued on Mar. 13, 2012, which is acontinuation-in-part of U.S. application Ser. No. 12/211,407 filed onSep. 16, 2008, which is a continuation-in-part of U.S. application Ser.No. 12/039,849 filed on Feb. 29, 2008, now U.S. Pat. No. 8,282,646issued on Oct. 9, 2012, which: (1) claims the benefit of U.S.Provisional Application No. 60/953,620 filed on Aug. 2, 2007, U.S.Provisional Application No. 60/947,813 filed on Jul. 3, 2007, U.S.Provisional Application No. 60/911,297 filed on Apr. 12, 2007, and U.S.Provisional Application No. 60/892,349 filed on Mar. 1, 2007; (2) is acontinuation-in-part of U.S. application Ser. No. 11/756,057 filed onMay 31, 2007, now U.S. Pat. No. 8,092,465 issued on Jan. 10, 2012, whichclaims the benefit of U.S. Provisional Application No. 60/812,694 filedon Jun. 9, 2006; (3) is a continuation-in-part of U.S. application Ser.No. 11/971,390 filed on Jan. 9, 2008, now U.S. Pat. No. 8,070,752 issuedon Dec. 6, 2011, which is a continuation-in-part of U.S. applicationSer. No. 11/363,548 filed on Feb. 27, 2006, now U.S. Pat. No. 7,780,672,issued on Aug. 24, 2010; and (4) is a continuation-in-part of U.S.application Ser. No. 12/025,414 filed on Feb. 4, 2008, now U.S. Pat. No.8,298,237 issued on Oct. 30, 2012, which claims the benefit of U.S.Provisional Application No. 60/953,637 filed on Aug. 2, 2007.

This application is a divisional of U.S. application Ser. No. 13/111,007filed on May 19, 2011, which is a continuation-in-part of U.S.application Ser. No. 12/872,663 filed on Aug. 31, 2010, now U.S. Pat.No. 8,407,067 issued on Mar. 26, 2013, which claims the benefit of U.S.Provisional Application No. 61/310,752 filed on Mar. 5, 2010.

This application is a divisional of U.S. application Ser. No. 13/111,007filed on May 19, 2011, which is a continuation-in-part of U.S.application Ser. No. 12/483,807 filed on Jun. 12, 2009, now U.S. Pat.No. 8,473,305 issued on Jun. 25, 2013, which is a continuation-in-partof U.S. application Ser. No. 12/371,096 filed on Feb. 13, 2009, which isa continuation-in-part of U.S. application Ser. No. 12/103,824 filed onApr. 16, 2008, now abandoned, which claims the benefit of U.S.Provisional Application No. 60/912,178 filed on Apr. 17, 2007.

This application is a divisional of U.S. application Ser. No. 13/111,007filed on May 19, 2011, which is a continuation-in-part of U.S.application Ser. No. 12/103,834 filed on Apr. 16, 2008, now U.S. Pat.No. 7,967,868 issued on Jun. 28, 2011, which claims the benefit of U.S.Provisional Application No. 60/912,178 filed on Apr. 17, 2007.

The disclosures of the above applications are incorporated herein byreference.

INTRODUCTION

The present teachings provide a patient-specific acetabular alignmentguide and related instruments for guiding an acetabular implant into theacetabulum of a patient.

SUMMARY

The present teachings provide an acetabular device. In one aspect, theacetabular system includes a patient-specific acetabular alignment guideincluding a bone engagement surface. The bone engagement surface has afirst portion configured and shaped to be conforming and complementaryto an acetabular rim surface and a second portion configured and shapedto be conforming and complementary to a periacetabular area of anacetabulum of a patient. The acetabular alignment guide includes aplurality of guiding formations extending through the second portion forguiding a plurality of alignment pins therethrough. The bone engagementsurface and the plurality of guiding formations are prepared from athree-dimensional model of the acetabulum of the specific patientreconstructed pre-operatively from a scan of the patient.

The acetabular device can also include an acetabular inserter includinga handle, a shaft and an acetabular coupler and a first alignmentadapter removably coupled to the shaft of the acetabular inserter. Thefirst alignment adapter includes a plurality of apertures configured tocorrespond to the guiding formations of the acetabular alignment guide,such that the alignment pins can pass through the apertures of thealignment adapter after the acetabular alignment guide is removedwithout removing the alignment pins from the patient.

The present teachings also provide a method for inserting an acetabularimplant into the acetabulum of a patient. The method includes engaging apatient-specific surface of the acetabular alignment guide to acomplementary rim surface and periacetabular area of a patient andinserting a plurality of alignment pins through corresponding alignmentapertures of the acetabular alignment guide and into the periacetabulararea of the patient. The method further includes removing the acetabularalignment guide without removing the alignment pins from the patient,guiding a first alignment adapter coupled to an acetabular inserter overthe alignment pins, and implanting the acetabular implant with theacetabular inserter.

The present teachings provide an acetabular device that includes anannular acetabular guide including a first surface and a second surfaceopposite to the first surface. The first surface is patient-specific andmade to conform to an acetabular rim surface around an acetabulum of apatient in accordance with a three-dimensional image of the acetabulumof the patient. The acetabular guide includes a cylindrical innerguiding surface oriented at patient-specific anteversion and abductionangles relative to the first surface. The acetabular device alsoincludes a patient-specific adapter having an outer surface mateablewith the inner surface of the acetabular guide and having aquick-connection component for coupling to a non-custom acetabularinstrument.

Further areas of applicability of the present teachings will becomeapparent from the description provided hereinafter. It should beunderstood that the description and specific examples are intended forpurposes of illustration only and are not intended to limit the scope ofthe present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is an exemplary illustration of a patient in preparation of anacetabular implant procedure;

FIG. 1A is a perspective view of an acetabular guide according to thepresent teachings, the acetabular guide shown in relation to a patient'sanatomy;

FIG. 2 is an environmental perspective view of the acetabular guide ofFIG. 1A shown with an acetabular inserter holding an acetabular implantaccording to the present teachings;

FIG. 3 is a perspective view of the acetabular inserter and acetabularimplant of FIG. 2;

FIG. 3A is a perspective environmental view of an acetabular implantillustrating rotation about an anatomic axis A during insertionaccording to the present teachings;

FIG. 3B is a perspective environmental view of an acetabular implantillustrating rotation about an anatomic axis B during insertionaccording to the present teachings;

FIG. 4 is an exploded view of the acetabular inserter and acetabularimplant of FIG. 3;

FIG. 4A is a perspective view of a modular reamer for use according tothe present teachings;

FIG. 4B is bottom plan view of a reamer head of the reamer of FIG. 4A;

FIG. 4C is a perspective view of a reamer driver of the reamer of FIG.4A;

FIG. 4D is bottom plan view of a distal end of the reamer driver of FIG.4C;

FIG. 4E is a perspective view of the modular reamer of FIG. 4A shownassembled with a an adaptor for use according to the present teachings;

FIG. 4F is top plan view of the adaptor of FIG. 4E;

FIG. 4G is bottom plan view of the adaptor of FIG. 4E;

FIG. 4H is an environmental view of an assembled of a reamer with apatient-specific adapter according to the present teachings;

FIG. 5 is a perspective environmental view of an exemplary acetabularalignment guide according to the present teachings;

FIG. 6 is a perspective environmental view of the acetabular alignmentguide of FIG. 5 shown with a plurality of guiding pins;

FIG. 7 is a perspective environmental view illustrating inserting anacetabular cup with an instrument guided by the guiding pins of FIG. 6;

FIG. 8 is a perspective environmental view of an exemplary acetabularimplant;

FIG. 9 is a perspective view of an exemplary impactor according to thepresent teachings;

FIG. 10 is a perspective view of an exemplary offset impactor accordingto the present teachings;

FIG. 11A is an environmental view of a patient-specific acetabular guideaccording to the present teachings;

FIG. 11B is an environmental view of a reamer patient-specific adapterguided for reaming the acetabulum by alignment pins placed using thepatient-specific acetabular guide of FIG. 11A;

FIG. 11C is an environmental view of a length scale for measuring alength of an implant, the scale guided by an alignment pin placed usingthe patient-specific acetabular guide of FIG. 11A;

FIG. 12 is a perspective view of a reamer with a patient-specificadapter guided for reaming the acetabulum by alignment pins placed usingthe patient-specific acetabular guide of FIG. 11A;

FIG. 13 is an environmental view of a patient-specific resurfacingfemoral implant according to the present teachings;

FIG. 14A is an environmental anterior view of a patient-specific femoralimplant according to the present teachings; and

FIG. 14B is an environmental anterior view of the femoral implant ofFIG. 14A.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is in no wayintended to limit the present teachings, applications, or uses.

The present teachings generally provide a patient-specific acetabularguide and associated inserter for use in orthopedic surgery, such as injoint replacement or revision surgery, for example. The patient-specificalignment guides can be used either with conventional orpatient-specific implant components prepared with computer-assistedimage methods. Computer modeling for obtaining three dimensional imagesof the patient's anatomy using MRI or CT scans of the patient's anatomy,the patient-specific prosthesis components, and the patient-specificguides and templates can be provided by various CAD programs and/orsoftware available, for example, by Materialise USA, Ann Arbor, Mich.

Patient-specific alignment guides and implants are generally configuredto match the anatomy of a specific patient. The patient-specificalignment guides are generally formed using computer modeling based onthe patient's 3-D anatomic image and have an engagement surface that ismade to conformingly contact and match a three-dimensional image/modelof the patient's bone surface (with or without cartilage or other softtissue), by the computer methods discussed above. The patient-specificalignment guides can include custom-made guiding formations, such as,for example, guiding bores or cannulated guiding posts or cannulatedguiding extensions or receptacles that can be used for supporting orguiding other instruments, such as drill guides, reamers, cutters,cutting guides and cutting blocks or for inserting pins or otherfasteners according to a surgeon-approved pre-operative plan. Thepatient-specific alignment guides can be used in minimally invasivesurgery, and in particular in surgery with multiple minimally-invasiveincisions. Various alignment guides and pre-operative planningprocedures are disclosed in commonly assigned and co-pending U.S. patentapplication Ser. No. 11/756,057, filed on May 31, 2007; U.S. patentapplication Ser. No. 12/211,407, filed Sep. 16, 2008; U.S. patentapplication Ser. No. 11/971,390, filed on Jan. 9, 2008, U.S. patentapplication Ser. No. 11/363,548, filed on Feb. 27, 2006; and U.S. patentapplication Ser. No. 12/025,414, filed Feb. 4, 2008. The disclosures ofthe above applications are incorporated herein by reference.

As disclosed, for example, in above-referenced U.S. patent applicationSer. No. 11/756,057, filed on May 31, 2007; in the pre-operativeplanning stage for a joint replacement or revision procedure, an MRIscan or a series of CT scans of the relevant anatomy of the patient,such as, for example, the entire leg of the joint to be reconstructed,can be performed at a medical facility or doctor's office. The scan dataobtained can be sent to a manufacturer. The scan data can be used toconstruct a three-dimensional image/model of the joint and provide aninitial implant fitting and alignment in a computer file form or othercomputer representation. The initial implant fitting and alignment canbe obtained using an alignment method, such as alignment protocols usedby individual surgeons.

The outcome of the initial fitting is an initial surgical plan that canbe printed or provided in electronic form with corresponding viewingsoftware. The initial surgical plan can be surgeon-specific, when usingsurgeon-specific alignment protocols. The initial surgical plan, in acomputer file form associated with interactive software, can be sent tothe surgeon, or other medical practitioner, for review. The surgeon canincrementally manipulate the position of images of implant components inan interactive image of the joint. Additionally, the surgeon can selector modify resection planes, types of implants and orientations ofimplant insertion. For example, the surgeon may select patient-specificanteversion and abduction angles for acetabular implants, as discussedbelow. After the surgeon modifies and/or approves the surgical plan, thesurgeon can send the final, approved plan to the manufacturer.

After the surgical plan is approved by the surgeon, patient-specificalignment guides can be developed using a CAD program or other imagingsoftware, such as the software provided by Materialise, for example,according to the surgical plan. Computer instructions of tool paths formachining the patient-specific alignment guides can be generated andstored in a tool path data file. The tool path can be provided as inputto a CNC mill or other automated machining system, and the alignmentguides can be machined from polymer, ceramic, metal or other suitablematerial, and sterilized. The sterilized alignment guides can be shippedto the surgeon or medical facility, for use during the surgicalprocedure.

The present teachings provide a patient-specific acetabular guide andassociated inserter for inserting an acetabular implant in theacetabulum of a patient's pelvis in a guided orientation at least aboutfirst and second non-parallel anatomic axes. Referring to FIGS. 1, 3Aand 3B, the first anatomic axis indicated at “A”, passes through theacetabulum 82 of a patient's pelvis 80 (only half of the pelvis isshown) and is oriented generally in a superior/inferior directionrelative to the patient. The second anatomic axis is indicated at “B”and is substantially perpendicular to the first axis A. As describedbelow, the present teachings provide instruments and methods forguiding, orienting and positioning an acetabular implant 200 at aselected angle of anteversion relative to the axis A, as shown in FIG.3A, and at a selected angle of abduction relative to the axis B, as alsoshown in FIG. 3B. The anteversion and abduction angles can be determinedinteractive or other surgeon input and can be patient-specific.

Referring to FIG. 1A, an exemplary acetabular guide 100 according to thepresent teachings can include a first surface 108 for engaging an areasurrounding the acetabulum 82 and a second surface 110 opposite to thefirst surface 108. The acetabulum-engaging first surface 108 can becustom-made or patient-specific to conform and mirror an acetabular rimsurface 84 around the acetabulum 82 of a specific patient by usingthree-dimensional image or model of the acetabulum and surroundingpelvic area of the patient, as described above. The first surface 108enables the acetabular guide to nest or closely mate relative to theacetabulum 82 of the patient.

The acetabular guide 100 can be temporarily and removably attached tothe pelvis 80 using temporary fasteners 120, such as bone nails ortacks, for example, passing through corresponding holes 104 through theacetabular guide 100. The acetabular guide 100 can be annular with anopening defined by an inner surface 102. The inner surface 102 can be,for example, a cylindrical surface. The inner surface 102 can beoriented relative to the first and second surfaces 108, 110 of theacetabular guide 100 to provide a selected anteversion angle about thefirst axis A and a selected abduction angle relative to the axis B, asshown in FIGS. 2, 3A and 3B. The anteversion and abduction angles can besurgeon-selected and patient-specific and can be determined with surgeoninput during the pre-operative planning for the specific patient.Anteversion angles can be, for example, in the range of about 10-20degrees forward relative to the first axis A, and adduction angles canbe in the range of about 40-50 degrees downward relative to the secondaxis B.

Referring to FIGS. 2-4, the acetabular guide 100 can be attached to thepelvis 80 around the acetabulum 72 after the acetabulum 82 has beenreamed and prepared for receiving the acetabular implant 200, such asthe Magnum™ acetabular cup commercially available from Biomet, Inc.,Warsaw, Ind. The acetabular implant 200 can be inserted into theprepared acetabulum 82 using an inserter 300 according to the presentteachings. The inserter 300, which can also function as an impactor, caninclude a handle 304 with a proximal impaction surface 318, a shaft 302and a guide-engaging portion 310 having a surface with a flat or planarportion 320. The guide-engaging portion 310 can have an outer surface312, which conforms to and is mateable with the inner surface 102 of theacetabular guide 100 for guiding the acetabular implant 200. The innersurface 102 and the outer surface 312 can be cylindrical.

Referring to FIG. 4, the inserter 300 can engage the acetabular implant200 via an intermediate member 250, such as the intermediate member ofthe Magnum™ system, which is commercially available from Biomet, Inc.,Warsaw, Ind. More specifically, the inserter 300 can include a distalportion 314, such as a ball-bearing bushing, which can be inserted andengage a receptacle 252 of the intermediate member 250. The acetabularimplant 200 can be mounted on the inserter 300 by aligning a pluralityof fingers 254 of the intermediate member 250 with correspondingcut-outs 202 on a peripheral edge of the acetabular implant 200. Theacetabular implant 200 can be secured to the inserter 300 by rotatingthe acetabular implant 200 relative to the insert 300 until a hand-tightfit is obtained.

Referring to FIG. 2, the inserter 300 with the acetabular implant 200mounted thereon can be directed toward the acetabular guide 100. Theouter surface 312 of the guide engaging portion 310 of the inserter 300can be brought into contact with the inner surface 102 of the acetabularguide 100, guiding the acetabular implant 200 toward the selectedanteversion and abduction orientation through the acetabular guide 100.The outer surface 312 of the guide engaging portion 310 can also providean impaction-depth feedback by alignment with the inner surface 102 ofthe acetabular guide. Full impaction of the acetabular implant 200 intothe acetabulum 82 can be indicated when planar portion 320 and/or outersurface 312 of the guide-engaging portion 310 of the inserter 300 areflush with and do not protrude over and above the second surface 110 ofthe acetabular guide 100. Depth indicia 322 can also be provided on theinserter shaft 302 or on the guide-engaging portion 310 of the inserter300, as shown in FIG. 2.

After the acetabular implant 200 is fully seated in the acetabulum 82 inthe selected anteversion and abduction orientations, the inserter 300and intermediate member 250 can be removed. The temporary fasteners 120can be removed and the acetabular guide released.

The acetabular guide 100 can be made of any biocompatible material, suchas metal, ceramic or polymer. The acetabular guide 100 can beconstructed by various manufacturing methods depending of the selectedmaterial, including, for example, machining, casting, molding,stereolithography or other layer deposition methods. In one aspect, theacetabular guide 100 can be made of disposable plastic material.

The patient-specific acetabular guide 100 can also be used with astandard (non patient-specific) modular reamer 331 fitted with apatient-specific reamer adapter 360 to ream the acetabulum of thespecific patient in pre-planned patient-specific orientations. Thisallows the acetabular implant 200 to be received in the selectedanteversion and abduction orientations, as shown in FIG. 4H anddiscussed in connection with FIGS. 4A-4H.

FIGS. 4A-4C illustrate an exemplary modular reamer 331 that includes areamer driver 330 and a reamer head 350. The reamer driver 330 can beremovably coupled to the reamer head 350 with a connecting mechanism335, which can be a spring-loaded, or snap-fit or other type ofreleasable connection, including connections secured with a set screw orother easily removable fasteners. An exemplary quick-connect connectionis illustrated in FIGS. 4A-4D and is also used to connect the reamer 331to the reamer adapter 360, as illustrated in FIGS. 4E-4H.

The reamer head 350 can be in the form of a hollow cup with asemi-spherical reaming surface 353 bounded by a periphery 351. Thereaming surface 353 defines a plurality of reaming formations or reamingteeth 357. A number of arms or rods 342 can be connected to theperiphery 351 and form a first component of the quick-connect mechanism335. The arms 342 can be attached to one another at a central hub 341forming a frame 343, as shown in FIG. 4B.

The reamer driver 330 can include a handle or sleeve 332 receiving adriver shaft 334 for coupling to a driver tool at a proximal end (notshown) and having a distal connector 338. The distal connector 338 formsa second component of the quick connect mechanism 335, which is operatedwith a spring-loaded slider or trigger 336 coupled to the driver shaft334. The distal connector 338 can include a number of openings or slots344 and a corresponding number of movable or retractable pins 346. Thenumber of slots 344 corresponds to the number of arms 342 and the slots344 are sized and shaped to receive the arms 342. Although four arms,slots and pins are illustrated, a smaller or greater number can be used,for example two or three arms, slots and pins that can be evenlypositioned radially about the reamer head 350. To connect the reamerdriver 330 to the reamer head 350, the slots 344 are placed over thearms 342 with the pins 344 in their retracted position. The pins 344 canbe retracted by moving the slider 336 in a direction away from thedistal connector 338. When the slider 336 is released, the arms 342 aregripped between the pins 344 and the walls of the slots 344 and thereamer driver 330 is securely connected to the reamer head 350.

Referring to FIGS. 4E-4H, the patient-specific reamer adapter 360 caninclude can include a first portion 362 and a second portion 368. Thefirst portion 362 can have an outer surface 364. The outer surface 364can be, for example, cylindrical. The outer surface 364 can be shaped,sized and oriented to mate with the inner surface 102 of thepatient-specific guide 100 to provide a selected and patient-specificanteversion angle about the first axis A and a selected abduction anglerelative to the axis B, as shown FIG. 4H. In this respect, the outersurface 364 of the adapter 360 is patient specific.

The reamer adapter 360 can be coupled to the reamer with a quick-connectconnection. For example, the reamer adapter 360 can be coupled betweenthe reamer driver 330 and the reamer head 350 with correspondingcomponents of the quick-connect mechanism 335 used for the connectingthe reamer driver 330 to the reamer head 350. Referring to FIGS. 4E-4H,the first portion 362 can include a number of arms 370 coupled to aproximal periphery 363 of the first portion 262 and are configured toengage the distal connector 338 of the reamer driver 330, i.e. to begripped in corresponding slots 344 by corresponding pins 346. In thisregard, the arms 370 of the first portion 362 provide a component thatis complementary to the quick-connect component of the reamer driver 330and complete a quick-connect mechanism 335 between the reamer drier 330and the reamer adapter 360.

Similarly, the second portion 368 of the reamer adapter 360 can includea quick-connect component complementary to the quick-connect componentof the reamer head 350 to complete the quick-connect mechanism 335. Morespecifically, the second portion 368 can include a number of slots 374and pin 372 for gripping the arms 342 of the reamer head 350.Accordingly, the same type of quick-connect mechanism 335 that is usedto couple the reamer driver 330 to the reamer head 350 can be used tocouple the reamer adapter 360 between the reamer driver 330 and thereamer head 350, as illustrated in FIGS. 4A and 4E. It is noted that thequick-connect mechanism 335 is not limited to the exemplary embodimentillustrated, but can be any quick-connect mechanism used fornon-patient-specific modular reamers, include snap-fit, taperedconnectors, threaded connectors, or any other connectors withcomplementary components “a” for the reamer driver 330 and “b” for thereamer head 350, which are then used in reverse order to couple thereamer adapter 360 therebetween in a sequence a-b-a-b. In theillustrated quick-connect mechanism 335, component “a” includes slotsand pins and component “b” includes arms.

Referring to FIG. 4H, the assembled reamer 331 with the patient-specificadapter 360 can be used with the patient-specific acetabular guide 100to ream the acetabulum 82 of the patient to receive an implant in aselected patient-specific orientation according to the pre-operativeplan. As described above in relation to FIGS. 1-4, the acetabular guide100 is attached to the acetabulum 82 in only one position, such that theinner surface 102 provides an orientation guide for the reamer head 350.In particular, the outer surface 364 of the reamer adapter 360 mates ina complementary close-fit manner with the inner surface 102 of theacetabular guide 100, such that the reamer head 350 can be oriented asspecified in the pre-operative plan to ream the acetabulum in theselected anteversion and abduction orientations relative to thecorresponding axes A and B. After the acetabulum 82 is reamed, theacetabular implant 200 can be impacted in the same selected orientationusing the inserter/impactor 300 discussed in connection with FIGS. 2 and3.

The exemplary acetabular guide 100 illustrated in FIGS. 1A, 2 and 4H isannular for placement around the acetabulum 82. In other embodiments, anacetabular guide 400 positioned only in a portion around the acetabulum82 can also be used. Referring to FIGS. 5-10, the patient-specificacetabular alignment guide 400 and other instruments for guiding anacetabular implant are illustrated. The patient-specific acetabularalignment guide 400 can be prepared during a pre-operative plan for thesurgical procedure based on a three-dimensional image of the relevantanatomy of the patient including portions of the pelvis 80, theacetabulum 82, the acetabular rim area 84, the periacetabular area andgenerally the hip joint of the patient. The three-dimensional image ofthe anatomy of the patient can be developed by commercially availablesoftware, as discussed above, using MRI, CT, X-rays or other scans ofthe particular patient.

Referring to FIGS. 5 and 6, the acetabular alignment guide 400 caninclude a first portion 402 configured and adapted to be positionedaround the rim surface 84 of the acetabulum 82 and a second portion 404configured and adapted to be positioned around the periacetabular areaof the pelvis 80 of a specific patient. The acetabular alignment guide400 can include a three-dimensional curved patient-specific boneengagement surface 408. The bone engagement surface 408 is defined tomatch complementarily to a portion of the acetabular rim surface 84 anda portion of an adjacent periacetabular area of the pelvis 80 of thepatient for close contact/nesting thereon in only one position andorientation. The second portion 404 of the acetabular alignment guide400 is designed during the pre-operative plan to define a plurality ofelongated through-slots, apertures or other guiding formations 406directed toward the periacetabular area for guiding a plurality ofalignment pins 420 parallel to an acetabular centering axis CC, thelocation and orientation of which is determined according to thepreoperative plan for the specific patient. The second portion 404 canbe reinforced with additional materials and/or have thicker dimensionsfor stability.

Three guiding formations 406 in the form of through holes and acorresponding number of alignment pins 420 are illustrated in FIGS. 5and 6. Depending on the patient and/or procedure, a different number ofguiding formations 406 and alignment pins 420 can be used. The alignmentpins 420 can be parallel defining a patient specific orientation andoperable for locating the acetabular centering axis CC. The alignmentpins 420 can removably guide along the same axis other instrumentsassociated with the insertion of an acetabular implant 200 after theacetabular alignment guide 400 is removed, as shown in FIG. 7, forexample. The orientation and location of the guiding formations 406 canbe patient-specific and determined pre-operatively to facilitate guidingand supporting the various instruments used for positioning, insertingand impacting the acetabular implant 200, as discussed below.

Referring to FIG. 7, after the alignment pins 420 have been insertedinto the bone, the acetabular alignment guide 400 can be removed. Anacetabular positioner or inserter or inserter/impactor 450 can be guidedby the alignment pins 420 for inserting the acetabular implant 200 inthe acetabulum. The inserter 450 can include a handle 451 with a knob453 and a shaft 452 coupled to a patient-specific alignment adapter 470.The patient-specific alignment adapter 470 can include an arm 474defining a plurality of alignment apertures 478 complementary to thealignment pins 420, such that the alignment adapter 470 can removablyslide over the alignment pins 420. In this respect, the shape and sizeof the arm 474 and the placement, arrangement and configuration of thealignment apertures 478 can be determined during the pre-operative planto correspond to the guiding formations 406 of the acetabular alignmentguide 400. The alignment adapter 470 can include a coupling opening 472for removably receiving the shaft 452 of the inserter 450 or can beintegrally coupled to the shaft 452 of the inserter 450. The couplingopening 472 can be, for example, an interference fitting or snap-on sideslot. Alternatively, the coupling opening 472 can be an enclosed hole,which receives the shaft 452 of the inserter 450, when the shaft ismodularly coupled to the inserter 450. The inserter 450 can be connectedto and disconnected from the acetabular implant 200 with a coupler 480at the distal end of the shaft 452 by rotating the knob 453. The coupler480 can also be modularly connected to the shaft 452. During insertionof the acetabular implant 200, the alignment pins 420 help stabilize,guide and secure the orientation of the inserter/impactor 450 andacetabular implant 200 and place the acetabular implant 220 in thedesired position and orientation relative to the acetabulum 82 asdetermined during the pre-operative plan using imaging scans of thepatient.

Similar patient-specific alignment adapters 470 can be used for guidingother type of inserters or impactors or reamers with reamer driverhandles or other instruments, such as, for example, reamers andimpactors that can be used during the preparation and implantationprocedure. Referring to FIGS. 9 and 10, first and second impactors (orother acetabular instruments) 500 a, 500 b are illustrated withrespective first and second patient-specific alignment adapters 470 a,470 b. The first impactor 500 a is an offset impactor 500 a generallyused for minimally invasive procedures, and the second impactor 500 b isstraight, non-offset impactor. Each of the first and second impactors500 a, 500 b can be modular and include a handle 502 respectivelycoupled to a first shaft 504 a or second 504 b terminating at a coupler510 with an end connector 512. The first shaft 504 a of the firstimpactor 500 a is offset relative to a longitudinal axis C (designed tocoincide with the acetabular centering axis CC) passing through thehandle 502 and the end connector 512. The shaft 504 b of the secondimpactor 500 b is coaxial with the handle 502.

As illustrated in FIG. 9, the offset first shaft 504 a can include acenter portion 505 c offset and substantially parallel to thelongitudinal axis C and first and second end portions 505 a, 505 bangled relative to the center portion 505 c for defining the offset. Thefirst end portion 505 a can be cannulated or hollow for receiving ashaft 492 of a driver 490 coupled to the end connector 512, such thatthe end connector 512 can be secured to the acetabular implant 200 byrotating a knob 494 of the driver 490. The first alignment adapter 470 aincludes a coupling opening 472 (enclosed hole or side opening/slot)through which the portion 505 a can pass through. As discussed above inconnection with alignment adapter 470 and the inserter 450 of FIG. 7,the shape and size of the arm 474 and the placement andarrangement/configuration of the alignment apertures 478 can bedetermined during the pre-operative plan to correspond to the guidingformations 406 of the acetabular alignment guide 400 and the locationand orientation of the alignment pins 420, such that the parallelalignment pins 420 can pass through the parallel alignment apertures 478to guide the first impactor 500 a relative to the acetabular implant 200and relative to the acetabulum 82. The first alignment adapter 470 a canbe removably coupled to the first impactor 500 a and can be slidablyadjusted in position relative to the first portion 505 a whilemaintaining the alignment orientation of the alignment apertures 406relative to axis CC and the alignment pins 420.

Referring to FIG. 10, the second impactor 500 b can be used similarly.Because the shaft 504 b is substantially straight (not offset), the endconnector 512 can be attached to the acetabular implant 200 by simplyrotating the handle 502 or a knob attached to the handle (not shown),similarly to the inserter 450 shown in FIG. 7. Each impactor 500 a, 500b can be modular, such that the handle 502, the shaft 504 a, 504 band/or the coupler 510 can be disassembled for removably mounting thealignment adapter 470 a, 470 b. Additionally, or alternatively, thecoupling opening 472 can be a snap-on side opening or side slot forremovably receiving the alignment adapter 470 a, 470 b withoutdisassembling the impactor 500 a, 500 b.

In some embodiments, the same alignment adapter can be used for morethan one conventional acetabular instrument. For example, the same thealignment adapter 470 (or 470 b) can be used optionally either with theinserter/impactor 450 or the impactor 500 b, or with an acetabularreamer, such as reamer 331.

It will be appreciated from the above discussion, that although thepatient-specific acetabular alignment guide 400 has an engagementsurface 408 that is complementary to the acetabular/periacetabular areaof the patient, the alignment adapters 470, 470 a and 470 b may or maynot have a patient-specific engagement surface as they are at a distanceaway from the bone surface during use. Rather, the location andarrangement of the alignment apertures 478 on the arm 474 ispatient-specific, such that the corresponding alignment adapter 470, 470a, 470 b can be mounted over the plurality of the alignment pins 420that have been already secured around the acetabulum 82 of the patientusing acetabular alignment guide 400.

The acetabular alignment guide 400 and the alignment adapters 470, 470a, 470 b can be made of disposable polymeric materials or any otherbiocompatible materials. The alignment adapters 470, 470 a, 470 b can beused with acetabular inserters, positioners, reamers, impactors andother instruments used during the acetabular procedure. The acetabularalignment guide 400 and one or more alignment adapters 470 can beprovided in a form of a kit with a set of alignment pins 420. Otherreusable, non custom instruments can be also included, for example, aninserter, reamer impactor, etc. The kit can include an acetabularimplant 200, which can be custom-made or non custom-made, as approvedand selected by the surgeon.

Referring to FIGS. 11A to 12, another patient-specific acetabular guide400′ is illustrated for use with a reamer 331′. As discussed above inconnection with acetabular guides 100 and 400, the acetabular guide400′, can include a first portion 402′ configured and adapted to bepositioned around the rim surface 84 of the acetabulum 82 and a secondportion 404′ configured and adapted to be positioned around theperiacetabular area of the pelvis 80 of a specific patient. Theacetabular alignment guide 400′ can include a three-dimensional curvedpatient-specific bone engagement surface 408′, which is the undersidesurface of the first and second portions 402′, 404′ that nestingly mateswith the specific patient's anatomy. In the exemplary embodimentillustrated in FIG. 11A, the first portion 402′ can extend around theentire inner rim surface 84 of the acetabulum and at least a portion ofthe acetabulum 82. Similarly, the second portion 404′ can extend aroundthe entire periacetabular area around the acetabulum 84 when additionalstability and attachment area is desired for the particular patient orpreferred by the surgeon. The bone engagement surface 408′ can bedesigned to match complementarily to portions of the acetabular rimsurface 84, of the acetabulum 82 and of an adjacent periacetabular areaof the pelvis 80 of the patient for close contact/nesting thereon inonly one position and orientation. The second portion 404′ of theacetabular alignment guide 400 is also designed during the pre-operativeplan to define a plurality of elongated through-slots, apertures orother guiding formations or holes 406′ directed toward theperiacetabular area for guiding a plurality of alignment pins 420parallel to the pre-determined acetabular centering axis CC, asdiscussed above in connection with FIGS. 5-7. After the alignment pins620 are secured to the bone, the acetabular guide 400′ can be removedleaving the alignment pins 420 for use with a reamer, as discussedbelow.

A reamer 331′ or 331″ can be guided by the alignments pins 420, as shownin FIGS. 11B and 12, respectively, along the acetabular centering axisCC. An off-the-shelf or standard (non custom) reamer 331′, 331″ can beused in combination with an adjustable or a patient-specific adapter470′, 470″. The adapter 470′ can include one or more arms 474′ (two arms474′ are illustrated in FIG. 11B). Each arm 474′ can be coupled to ashaft 330′ of the reamer 431′ with a quick-coupling arrangement 474′,which can be, for example, an opening in the arms configured forreceiving the shaft 330′ or other coupler. Each arm 474′ can include atleast one opening 478′ positioned and configured for receiving acorresponding alignment pin 420, which is secured to the bone in apredetermined position and orientation using the patient-specificalignment guide 400′ through a corresponding hole 406 of the guide 400″.Accordingly, the location and orientation of the openings 478′ on thearms 474′ and relative to the acetabular centering axis CC arepatient-specific. In some embodiments, an arm 474′ can include more thanone opening 478′. The arms 474′ can be integrally attached to oneanother, or modularly or separately coupled to the shaft 330′. One ofthe alignment pins, pin 420′ for example, can provide a fixed point ofreference for measuring the length of the leg of the patient fordetermining the length of an implant 200′ and the depth in thecorresponding intramedullary canal. The implant 200′ can include a head203′ and a stem 201′, as shown in FIG. 11C. A scale or other measuringdevice 477 can be coupled to the pin 420′ for measuring the length andsizing the implant 200′. The scale 477 can be slidably placed over thepin 477′ as shown in FIG. 11B. The length can be measured beforeimplantation and also-post implantation (as shown in FIG. 11B) forconfirming proper impaction and placement of the implant.

Referring to FIG. 12, a non-custom reamer 331″ can be coupled with apatient-specific adapter 470″ designed to slide over the alignment pins420, after the alignment pins 420 are secured on the patient's pelvis 80in a patient-specific configuration, position and orientation, whichalso determines the acetabular centering axis CC, as discussed above inconnection with FIGS. 5-7. In the embodiment illustrated in FIG. 12, theadapter 470″ can be monolithic and include two arms 474″ for receivingrespectively two alignment pins 420 through corresponding openings 478″,although different number of arms 474″ can be used and each arm 474″ caninclude more than one opening 478″ for receiving more than one pin 420.The adapter 470″ can by coupled to the reamer 331″ with a quick-connectto the shaft of the reamer 331″, as described above in relation to FIGS.4A-4G, or with another type of connection 335″, such as snap-fit orthreadable socket or bayonet coupling. The reamer 331″ can be of theblade type, including reaming blades 333″. In one embodiment, the blades333″ can be removable, replaceable and/or disposable. Each blade 333″can be semicircular or quarter-circular and can be attached to a chuckor other support 337″ of the reamer 331″ with set screws or grooves orjaws.

In some procedures, the acetabular implant 200 discussed above can beused to articulate with a patient-specific resurfacing or replacementproximal femoral component, as shown in FIGS. 13, 14A and 14B. Forexample, a patient-specific resurfacing implant can be designed duringthe pre-operative plan based on image models reconstructed from scans ofthe patient.

Referring to FIG. 13, when the femoral head 92 is salvageable and neednot be resected and replaced, the diseased or defective surface of thefemoral head 92 can be identified in the image. A femoral component 600can be designed to replace the defective portions, such as poor bonequality and/or avascular regions of the femoral head 92. The femoralcomponent 600 can include a dome-shaped portion or dome 602 with anouter convex articulating surface 603 for articulating with anacetabular implant or the patient's natural acetabulum and an inner boneengagement surface 604 that is designed to match and be complementaryand match the surface of the femoral head 92 with or without soft tissueattached, as determined in the pre-operative plan. The dome 602 can havea periphery 608 designed such that the dome covers and resurfaces allthe defective portions of the femoral head 92. The femoral component 600can have a short stem 606, which is inserted through the femoral head 92and secured into the femoral neck 94. The stem 606 can be designedduring the preoperative plan based on the three-dimensionalreconstruction of the patient's anatomy from the patient's scans suchthat the axis of the stem D is placed in a selected position andorientation relative to the neck 94 of the patient's and in a selectedanteversion orientation relative to the proximal femur 90. Additionally,the length of the stem 606 and the size and shape of the cross-section607 along the length of the stem 606 can also be designed based on thepreoperative plan and the reconstruction model of the neck 94 of thepatient, such that bone preservation and adequate attachment support arebalanced and/or optimized for the particular patient.

Referring to FIGS. 14A and 14B, a patient-specific femoral implant 618for a proximal femur in which the femoral head 92 is resected caninclude a femoral head component 620, a femoral neck component 624 and afemoral stem component 622. The femoral implant 618 can be designedduring the preoperative plan based on the three-dimensionalreconstruction of the patient's anatomy from the patient's scans suchthat the femoral head implant 620 and femoral neck component 624cooperate to retain the axis D and the center of rotation R of thepatient's femur or acetabulum, based on surgeon determination andpreference. The femoral neck component 624 can be designed to match thepatient's femoral neck 94 in size and orientation. The femoral stemimplant 622 can be selected from standard (non custom) stem sizes) orcan be customized for length, cross-section and/or shape for thespecific patient.

The foregoing discussion discloses and describes merely exemplaryarrangements of the present teachings. Furthermore, the mixing andmatching of features, elements and/or functions between variousembodiments is expressly contemplated herein, so that one of ordinaryskill in the art would appreciate from this disclosure that features,elements and/or functions of one embodiment may be incorporated intoanother embodiment as appropriate, unless described otherwise above.Moreover, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims,that various changes, modifications and variations can be made thereinwithout departing from the spirit and scope of the present teachings asdefined in the following claims.

What is claimed is:
 1. A method for inserting an acetabular implant intoan acetabulum of a patient, the method comprising: engaging apatient-specific surface of an acetabular alignment guide to acomplementary rim surface and periacetabular area of a pelvis outsidethe acetabulum of the patient; wherein the patient-specific surface ofthe acetabular alignment guide includes a three-dimensional anatomicengagement surface configured to conform and match to athree-dimensional bone surface of the rim and the periacetabular area ofthe pelvis of the patient; inserting a plurality of alignment pinsthrough corresponding alignment apertures of the acetabular alignmentguide and into the periacetabular area of the pelvis outside theacetabulum of the patient; removing the acetabular alignment guidewithout removing the alignment pins from the periacetabular area of thepelvis of the patient; guiding a first alignment adapter coupled to anacetabular inserter over the alignment pins; and implanting theacetabular implant in the acetabulum with the acetabular inserter, theacetabular inserter holding the acetabular implant.
 2. The method ofclaim 1, wherein guiding a first alignment adapter coupled to anacetabular implant inserter over the alignment pins comprises insertingthe alignment pins through complementary apertures of the firstalignment adapter.
 3. The method of claim 1, further comprising:removing the acetabular inserter and the first alignment adapter;guiding a second alignment adapter coupled to an impactor over thealignment pins; and impacting the acetabular implant with the impactor.4. The method of claim 3, wherein guiding a second alignment adaptercoupled to an impactor over the alignment pins comprises inserting thealignment pins through complementary apertures of the second alignmentadapter.
 5. The method of claim 4, wherein the first and secondalignment adapters are identical.
 6. The method of claim 4, wherein theimpactor is an offset impactor having a drive shaft offset relative to acenter axis of the second alignment adapter and wherein the first andsecond alignment adapters are different.
 7. A method for inserting anacetabular implant into an acetabulum of a patient, the methodcomprising: engaging a first portion of a patient-specific acetabularalignment guide to a portion of a rim surface of the acetabulum of apelvis of the patient, the first portion shaped to be conforming only tothe rim surface without extending into the acetabulum of the pelvis ofthe patient; engaging a second portion of the patient-specificacetabular alignment guide to a periacetabular area outside theacetabulum of the patient, the second portion shaped to be conforming tothe periacetabular area of the pelvis of the patient; wherein the firstand second portions of the patient-specific acetabular alignment guideinclude three-dimensional anatomic engagement surfaces configured toconform and match to three-dimensional bone surfaces of the rim and theperiacetabular area of the pelvis of the patient; inserting a pluralityof alignment pins through corresponding alignment apertures of thesecond portion of the acetabular alignment guide and into theperiacetabular area of the pelvis of the patient; removing theacetabular alignment guide without removing the alignment pins from thepelvis of the patient; guiding the acetabular implant into theacetabulum using the alignment pins; wherein guiding the acetabularimplant into the acetabulum using the alignment pins includes: guiding afirst alignment adapter coupled to an acetabular inserter over thealignment pins; and implanting the acetabular implant into theacetabulum with the acetabular inserter.
 8. The method of claim 7,wherein guiding a first alignment adapter coupled to an acetabularimplant inserter over the alignment pins comprises inserting thealignment pins through complementary apertures of the first alignmentadapter.
 9. The method of claim 7, further comprising: removing theacetabular inserter and the first alignment adapter; guiding a secondalignment adapter coupled to an impactor over the alignment pins; andimpacting the acetabular implant with the impactor.
 10. The method ofclaim 9, wherein guiding a second alignment adapter coupled to animpactor over the alignment pins comprises inserting the alignment pinsthrough complementary apertures of the second alignment adapter.
 11. Themethod of claim 9, wherein the first and second alignment adapters areidentical.
 12. The method of claim 9, wherein the impactor is an offsetimpactor having a drive shaft offset relative to a center axis of thesecond alignment adapter and wherein the first and second alignmentadapters are different.
 13. The method of claim 7, wherein the firstalignment adaptor has a patient-specific surface and is slidablerelative to the acetabular inserter.
 14. A method for inserting anacetabular implant into an acetabulum of a patient, the methodcomprising: engaging a first portion of a patient-specific acetabularalignment guide to a portion of a rim surface of the acetabulum of apelvis of the patient, the first portion shaped to be conforming only tothe rim surface without extending into the acetabulum of the patient;engaging a second portion of the patient-specific acetabular alignmentguide to a periacetabular area outside the acetabulum of a patient, thesecond portion shaped to be conforming to the periacetabular area of thepelvis of the patient and having a plurality of patient-specificalignment bores; wherein the first and second portions of thepatient-specific acetabular alignment guide include three-dimensionalanatomic engagement surfaces configured to conform and match tothree-dimensional bone surfaces of the rim and the periacetabular areaof the pelvis of the patient; inserting a plurality of alignment pinsthrough the corresponding alignment bores of the second portion of theacetabular alignment guide and into the periacetabular area of thepelvis of the patient; removing the acetabular alignment guide withoutremoving the alignment pins from the periacetabular area of the pelvisof the patient; guiding a patient specific alignment adapter having aplurality of alignment bores complementary to the alignment bores of thesecond portion of the acetabular alignment guide over the alignmentpins; coupling an acetabular inserter to the patient-specific alignmentadapter; coupling the acetabular implant to the acetabular inserter; andimplanting the acetabular implant into the acetabulum by sliding thepatient specific alignment adaptor coupled to the acetabular inserteralong the alignment pins.
 15. The method of claim 14, wherein couplingan acetabular inserter to the patient-specific alignment adaptorcomprises passing a shaft of the acetabular inserter through a snap-onside opening of the alignment adapter.
 16. The method of claim 14,wherein coupling an acetabular inserter to the patient-specificalignment adaptor comprises removably coupling a shaft of the acetabularinserter to the alignment adapter parallel to the alignment bores of thealignment adapter.
 17. The method of claim 14, wherein the alignmentadaptor has a patient-specific surface and is slidable relative to theacetabular inserter.
 18. The method of claim 14, further comprising:removing the acetabular inserter; coupling the alignment adapter to animpactor; and impacting the acetabular implant with the impactor. 19.The method of claim 18, wherein the impactor has a handle and a shaftoffset from the handle.